Applicability of stroke volume variation in patients of a general intensive care unit: a longitudinal observational study

Changes in stroke volume induced by lung recruitment maneuver can predict fluid responsiveness during intraoperative lung-protective ventilation in prone position

Background

The present study aimed to evaluate the reliability of hemodynamic changes induced by lung recruitment maneuver (LRM) in predicting stroke volume (SV) increase after fluid loading (FL) in prone position.

Methods

Thirty patients undergoing spine surgery in prone position were enrolled. Lung-protective ventilation (tidal volume, 6–7 mL/kg; positive end-expiratory pressure, 5 cmH₂O) was provided to all patients. LRM (30 cmH₂O for 30 s) was performed. Hemodynamic variables including mean arterial pressure (MAP), heart rate, SV, SV variation (SVV), and pulse pressure variation (PPV) were simultaneously recorded before, during, and at 5 min after LRM and after FL (250 mL in 10 min). Receiver operating characteristic curves were generated to evaluate the predictability of SVV, PPV, and SV decrease by LRM (ΔSV_LRM) for SV responders (SV increase after FL > 10%). The gray zone approach was applied for ΔSV_LRM.

Results

Areas under the curve (AUCs) for ΔSV_LRM, SVV, and PPV to predict SV responders were 0.778 (95% confidence interval: 0.590–0.909), 0.563 (0.371–0.743), and 0.502 (0.315–0.689), respectively. The optimal threshold for ΔSV_LRM was 30% (sensitivity, 92.3%; specificity, 70.6%). With the gray zone approach, the inconclusive values ranged 25 to 75% for ΔSV_LRM (including 50% of enrolled patients).

Conclusion

In prone position, LRM-induced SV decrease predicted SV increase after FL with higher reliability than traditional dynamic indices. On the other hand, considering the relatively large gray zone in this study, future research is needed to further improve the clinical significance.

Trial registration

UMIN Clinical Trial Registry UMIN000027966. Registered 28th June 2017.

Impact of deep breathing on predictability of stroke volume variation in spontaneous breathing patients

BACKGROUND

This study investigated the ability of stroke volume variation (SVV) during deep breathing to discriminate fluid responders among spontaneously breathing patients.

METHODS

Thirty patients undergoing general anaesthesia were enrolled and assessed before anaesthetic induction. Haemodynamic variables, including stroke volume (SV) and SVV, were measured using the ClearSight system during normal breathing. After these measurements, each patient was required to maintain deep breathing (6 breaths min^-1 ) and haemodynamic variables were recorded. Then, the table was adjusted to the Trendelenburg position (15°) for 2 minutes, and haemodynamic variables were measured. Receiver operating characteristic curves were created for SVV during normal and deep breathing, and the difference in SVV between normal and deep breathing (ΔSVV) to discriminate fluid responders (SV increase >10% after changing position). The correlation between SV increase and ΔSVV was examined using Pearson's correlation coefficient. The grey zone approach was used to assess the inconclusive range of the haemodynamic variables.

RESULTS

Receiver operating characteristic curve analysis indicated that ΔSVV showed good reliability in predicting fluid responsiveness (AUC: 0.850; 95% CI: 0.672-0.953; threshold: 4%, sensitivity: 75.0%, specificity: 88.9%], while SVV during normal breathing did not (AUC: 0.579; 95% CI: 0.386-0.756)]. Although SVV during deep breathing exhibited acceptable predictability (AUC: 0.778; 95% CI: 0.589-0.908), the sensitivity was not good (58.3%). With the grey zone approach, the inconclusive range of ΔSVV was small with the range of 1.4%-4.2% (23% of patients).

CONCLUSION

Deep breathing could improve the reliability of dynamic indices in spontaneously breathing patients.

TRIAL REGISTRATION

UMIN-CTR, identifer: UMIN000027970. https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000032040.

[Treatment of acute necrotizing pancreatitis]

Acute pancreatitis (AP) has an annual incidence of 30-45 per 100,000 inhabitants. In Germany approximately one third of the cases are of biliary or alcoholic origin. The diagnosis is based on the typical epigastric pain with radiation and a threefold increase of lipase or amylase in serum. Imaging procedures only rarely need to be included for the primary diagnostics. An early risk assessment is important to be able to allocate patients with severe AP to surveillance in an intensive care unit (ICU). Elevation of blood urea nitrogen, hematocrit and blood glucose are early predictors of poor outcome.The removal of impacted gall-stones by endoscopic retrograde cholangiography (ERC) is the only causal treatment of biliary AP, which must be carried out when there are signs of cholangitis and in severe biliary AP. Pain management and early fluid substitution are the most important symptomatic approaches. In the early phase of AP 150-250 ml/h of crystalloid solution should be administered to compensate for the extravasal loss of fluid. In certain cases, the initial fluid requirement might be even higher. In the ICU setting echocardiography and advanced hemodynamic monitoring are available for guidance. Prophylactic antibiotic treatment is not recommended in mild AP and it is a matter of debate even in severe AP. Early enteral nutrition has been shown to improve the outcome. Even in cases of fluid collection and necrosis a primary surgery approach should be avoided in favor of a "step-up" procedure with radiologically guided drainage as well as endoscopic and if necessary video-assisted percutaneous retroperitoneal débridement. Surgery remains an option for complications and for infected necrosis which cannot be reached by any other means.

Preemptive volume therapy to prevent hemodynamic changes caused by the beach chair position: hydroxyethyl starch 130/0.4 versus Ringer's acetate-a controlled randomized trial

BACKGROUND

Hemodynamic instability frequently occurs in beach chair positioning for surgery, putting patients at risk for cerebral adverse events. This study examined whether preoperative volume loading with crystalloids alone or with a crystalloid-colloid combination can prevent hemodynamic changes that may be causative for unfavorable neurologic outcomes.

METHODS

The study randomly assigned 43 adult patients undergoing shoulder surgery to 3 study groups. Each group received an infusion of 500 mL of Ringer's acetate between induction of anesthesia and being placed in the beach chair position. The crystalloid group received an additional bolus of 1000 mL Ringer's acetate. The hydroxyethyl starch group was administered an additional bolus of 500 mL of 6% hydroxyethyl starch 130/0.4. Hemodynamic monitoring was accomplished via an esophageal Doppler probe. Cerebral oxygen saturation was examined with near-infrared spectroscopy. Changes in stroke volume variation between the prone and beach chair positions were defined as the primary outcome parameter. Secondary outcomes were changes in cardiac output and cerebral oxygen saturation.

RESULTS

The control group was prematurely stopped after enrollment of 4 patients because of adverse events. In the hydroxyethyl starch group, stroke volume variation remained constant during positioning maneuvers (P = .35), whereas a significant increase was observed in the Ringer's acetate group (P < .01; P = .014 for intergroup comparison). This was also valid for changes in cardiac output. Cerebral oxygen saturation significantly decreased in both groups.

CONCLUSIONS

Preprocedural boluses of 500 mL of 6% hydroxyethyl starch 130/0.4 as well as 1000 mL of Ringer's acetate were efficient in preserving hemodynamic conditions during beach chair position.

Mandatory criteria for the application of variability-based parameters of fluid responsiveness: a prospective study in different groups of ICU patients

BACKGROUND AND OBJECTIVE

Stroke volume variation (SVV) has high sensitivity and specificity in predicting fluid responsiveness. However, sinus rhythm (SR) and controlled mechanical ventilation (CV) are mandatory for their application. Several studies suggest a limited applicability of SVV in intensive care unit (ICU) patients. We hypothesized that the applicability of SVV might be different over time and within certain subgroups of ICU patients. Therefore, we analysed the prevalence of SR and CV in ICU patients during the first 24 h of PiCCO-monitoring (primary endpoint) and during the total ICU stay. We also investigated the applicability of SVV in the subgroups of patients with sepsis, cirrhosis, and acute pancreatitis.

METHODS

The prevalence of SR and CV was documented immediately before 1241 thermodilution measurements in 88 patients.

RESULTS

In all measurements, SVV was applicable in about 24%. However, the applicability of SVV was time-dependent: the prevalence of both SR and CV was higher during the first 24 h compared to measurements thereafter (36.1% vs. 21.9%; P<0.001). Within different subgroups, the applicability during the first 24 h of monitoring ranged between 0% in acute pancreatitis, 25.5% in liver failure, and 48.9% in patients without pancreatitis, liver failure, pneumonia or sepsis.

CONCLUSIONS

The applicability of SVV in a predominantly medical ICU is only about 25%-35%. The prevalence of both mandatory criteria decreases over time during the ICU stay. Furthermore, the applicability is particularly low in patients with acute pancreatitis and liver failure.

Journal of Clinical Monitoring and Computing 2017 end of year summary: cardiovascular and hemodynamic monitoring

Hemodynamic monitoring provides the basis for the optimization of cardiovascular dynamics in intensive care medicine and anesthesiology. The Journal of Clinical Monitoring and Computing (JCMC) is an ideal platform to publish research related to hemodynamic monitoring technologies, cardiovascular (patho)physiology, and hemodynamic treatment strategies. In this review, we discuss selected papers published on cardiovascular and hemodynamic monitoring in the JCMC in 2017.

Advanced hemodynamic monitoring in intensive care medicine : A German web-based survey study

BACKGROUND

Advanced hemodynamic monitoring is recommended in patients with complex circulatory shock.

OBJECTIVES

To evaluate the current attitudes and beliefs among German intensivists, regarding advanced hemodynamic monitoring, the actual hemodynamic management in clinical practice, and the barriers to using it.

MATERIALS AND METHODS

Web-based survey among members of the German Society of Medical Intensive Care and Emergency Medicine.

RESULTS

Of 284 respondents, 249 (87%) agreed that further hemodynamic assessment is needed to determine the type of circulatory shock if no clear clinical diagnosis can be made. In all, 281 (99%) agreed that echocardiography is helpful for this purpose (transpulmonary thermodilution: 225 [79%]; pulmonary artery catheterization: 126 [45%]). More than 70% of respondents agreed that blood flow variables (cardiac output, stroke volume) should be measured in patients with hemodynamic instability. The parameters most respondents agreed should be assessed in a patient with hemodynamic instability were mean arterial pressure, cardiac output, and serum lactate. Echocardiography is available in 99% of ICUs (transpulmonary thermodilution: 91%; pulmonary artery catheter: 63%). The respondents stated that, in clinical practice, invasive arterial pressure measurements and serum lactate measurements are performed in more than 90% of patients with hemodynamic instability (cardiac output monitoring in about 50%; transpulmonary thermodilution in about 40%). The respondents did not feel strong barriers to the use of advanced hemodynamic monitoring in clinical practice.

CONCLUSIONS

This survey study shows that German intensivists deem advanced hemodynamic assessment necessary for the differential diagnosis of circulatory shock and to guide therapy with fluids, vasopressors, and inotropes in ICU patients.